Process of treating ores.



No. 739,011. PATENTED SEPT. 15, 1903. E. LAIST. PROCESS 0E TEEATING GEES.

APPLICATION FILED NOV.12, 1902.

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No. 739,01'i.

UNITED STATES satented September 15,

PATENT OEEICE.l

EREDERIOK LAIST, OE SALT LAKE OITY, UTAH, ASSIGNOR OE TwO-THIRDS To HUDSON SMITH AND PETER O. BROWN, OE SALT LAKE OITY, UTAH.

PROCESS OF TREA-rlNG OREs.

SPECIFICATION forming part of Letters Patent No. 739,011, dated September 15, 1903. I

Application iiled November 12, 1902. Serial No. 131,052. (No specimens.) l

To all whom t may concern:

Be itknown that I, FREDERICK LAIsT,a citizen of the United States,and a resident of Salt Lake City, county of Salt Lake, State of Utah, have invented a new and useful Process of Treating Orcs, of which the following is a specification. l

This invention is a method for the treatment of ores wherein the solvent liquid and also the precipitant are regenerated. The method is essentially cyclical in character, and the fuel and air employed during certain steps'of the method are the only materials which are directly consu med. The chemical reagents employed need only to be added in quantity sufcient to replace the unavoidable losses of manufacture. The method is particularly applicable to the treatment of copper ores and will'be vso described. It is to be understood, however, that it isnot necessarily limited to the treatment of these particular ores,

According to my invention the copper ore is crushed and subjected to the action of a suitable solvent, as sulfuric acidor ammonia. In case the carbonate of copper/is treated the dissolving-tank is preferably closed and provided with suitable means for collecting the evolved carbon dioxid. The copper solution resulting from this treatment is separated from the residual ore by any usual method of decantation or filtration and transferred to the precipitation-tanks, which may conveniently comprise a series of covered tanks provided withl means for commingling the The precipitated suld of copper is removed precipitant and the solution. Here the copper is precipitated as suliid by a suitable reagent, preferably hydrogen sulfid, and the solvent liquoris regenerated. Instead of precipitating the copper in closed tanks, as described, any suitable device for bringing the gas and liquid into intimate contact may be employed-as, for instance, a tower such as is commonly used for the absorption of hydrochloric acid. If the solvent employed is sulfuric acid, the precipitation will take place in accordance with the reaction (I) OusOd-ms:crisi-mso,l

by ltration or otherwise to be treated as hereinafter described, and the regenerated vcopper is obtained. in sulfur dioKid are preferably employed as solvent is returned to the dissolving-tanks for 4the treatment of further quantities of ore.

The hydrogen sulfid necessary for the precipitation of the copper is preferably obtained by reaction between carbon dioxid and asuitable alkaline-earth sulfd in the presence of water. l. preferably employ calcium suliid for this purpose, stirring the same into a thin mud with water and injectingcarbon dioxid. Other sulfide-as, for instance, those of barium or strontium-may of course be substituted for the calcium suliid. The generation of the hydrogen sulfid may be effected in a covered tank or series of tanks similar to those employed for the precipitation of the sulfld of copper or in any other suitable device. The reaction whereby the hydrogen Sulfid is generated proceeds according to the equation the precipitate being substantially pure car- Vbonate of calcium. This calcium carbonate is subjected in suitable absorption-chambers to the action of gases rich in sulfur dioxid, said gases being preferably obtained as a byproduct Afrom the treatment of the precipi- By the absorption of these gases the calcium carbonate is converted into sulfite in accord* ance with the equation a corresponding quantity of carbon dioxid being set free. Said sulfite is thereafter reduced by carbon to sulfd, according to the reaction This reduction is best accomplished in a specially-constructed furnace, wherein the mixture may beheated to bright redness in a reducing atmosphere, the sulfid being tapped out from time to` time. The precipitated copper sulfld is melted and subjected to the usual converting process whereby metallic The escaping gases rich above described for the conversion of calcium carbonate to calcium suliite.

The calcium sullid required at the incep- Atated copper sulfid as hereinafter described.

ICO

tion ot' the process is conveniently obtained by the reduction of calcium sulfate by carbon. Thereafter it will preferably be derived, as described, by reduction of the corresponding sulfite formed during the process. It will thus be seen that the solvent liquor-in the specific example given sulfuric acid-is regenerated, as is also the precipitant, hydrogen sultid. This latter reagent is obtained by the interreaction of two com pounds-calcium sultid and carbon dioxid-both of which are formed during the regular course of the operation.

Reference'is made to the accompanying sheet of drawings, wherein the several steps of my method are diagrammatically illustrated. In this diagram the steps, as hereinbefore outlined, are expressed as chemical equations, and arrows are so placed as to indicate the manner in which each product is formed and the manner in which it enters into the cycle of my method. This diagram is for purposes of convenience based upon the treatment of a specific ore by a specific solvent and precipitant. It will be understood, however, that it is merely represent-ative of a single specific application of the general method. The raw material and the nal product are indicated for convenience in heavy characters.

I claim- 1. The herein-described method of generating hydrogen sulid and precipitating copper, which consists in subjecting an alkalineearth sulfid suspended in water to the action of carbon dioxid, thereby generating hydrogen sulfid and precipitating the carbonate of the alkaline-earth metal, conducting said hydrogen sulfid into the presence of copper in solution, thereby precipitating copper sulfid and forming a solvent liquid, and treating copper ores with said solvent liquid, substantially as described.

2. The herein-described method of generating hydrogen suld and precipitating copper which consists in subjecting an alkalineearth sulfid in the presence 0f Water to the action of carbon dioxid, thereby producing hydrogen suliid and the carbonate of the a1- kaline earth, conducting said hydrogen sulfid into the presence of copper in solution thereby precipitating copper sulfid, treating said copper suliid to obtain therefrom metallic copper and gases rich in sulfur dioxid, absorbing said gases by an alkaline-earth carbonate, thereby forming the sulfite of the alkaline earth, and reducing the said sulfite to sulfid, substantially as described.

3. The hereindescribed cyclical method for extracting copper from ores and compounds, which consists in dissolving the copper from said ores, treating the solution with hydrogen suld to precipitate the copper as suld, melting said sulfid and converting it into metallic copper and gases rich in sulfur dioxid, reacting with said gases upon an alkaline-earth carbonate thereby producing carbon dioxid and an alkaline-earth sultite, reducing the said sulite to sulfid, generating hydrogen sullid by reaction between said alkaline-earth sulfid and carbon dioxid in presence of water, and utilizing said hydrogen suld for the precipitation of additional quantities of copper sulfid, substantially as described.

4. The herein-described method of generating hydrogen sulfid and precipitating copper, which consists in subjecting an alkalineearth sultid in presence of Water to the action of carbon dioxid, therebygenerating hydrogen suld and precipitating the carbonate of the alkaline-earth metal, conducting said hydrogen sulfid into the presence of copper in solution, thereby precipitating copper sulfid and forming a solvent liquid, treating copper ores with said solvent liquid, and collecting said alkaline-earth carbonate and reconverting it into sulfid, substantially as described.

In testimony Whereof I affix my signature, in presence of two witnesses,at Salt Lake City, Utah, October 14, A. D. 1902.

FREDERICK LAIST.

Witnesses:

HUDSON SMITH, A. C. SADLER. 

